US4438833A - Piston for a pneumatic, hydraulic, or hydropneumatic installation - Google Patents

Piston for a pneumatic, hydraulic, or hydropneumatic installation Download PDF

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Publication number
US4438833A
US4438833A US06/306,383 US30638381A US4438833A US 4438833 A US4438833 A US 4438833A US 30638381 A US30638381 A US 30638381A US 4438833 A US4438833 A US 4438833A
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US
United States
Prior art keywords
piston
throttled
channel
cylinder
axial bore
Prior art date
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Expired - Fee Related
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US06/306,383
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English (en)
Inventor
Willi Schafer
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Stabilus GmbH
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Stabilus GmbH
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Assigned to STABILUS GMBH; HERBERICHSTRASSE, A GERMAN CORP reassignment STABILUS GMBH; HERBERICHSTRASSE, A GERMAN CORP ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: SCHAFER, WILLI
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
    • F16F9/32—Details
    • F16F9/34—Special valve constructions; Shape or construction of throttling passages
    • F16F9/344—Vortex flow passages

Definitions

  • the present invention relates to an improved piston adapted to be used in a pneumatic, hydraulic, or hydropneumatic installation.
  • Installations of the type referred to typically include a cylinder, a piston slidably housed within the cylinder and being provided with damping means and being connected to a piston rod, the cavity of the cylinder being filled with gas and/or liquid and being separated by the piston into two working chambers, the piston rod extending through guiding and sealing means provided at one end of the cylinder, and the damping means comprising a constantly open throttled passage between said working chambers.
  • German Gebrauchmuster No. 7,833,144 describes, for example, a gas spring having a constantly open passage between the working chambers, the passage being defined by a throttled bore through the piston extending parallel to the axis of the piston.
  • This throttled bore is effective only when the piston rod moves out of the cylinder and is adapted to limit the rate of movement of the piston rod out of the cylinder to a predetermined measure.
  • these throttled bores have a cross-section of about from 0.3 to 0.4 mm ⁇ to achieve the desired damping effect. Due to this narrow cross-section, the bores are susceptible to clogging, as even extremely small impurities can occlude this cross-section. Furthermore, these bores must be made very precisely to maintain the damping effect within the required tolerance.
  • the constantly open throttled passage comprises at least one spiral throttled channel extending in a plane perpendicular to the axis of the piston.
  • the spiral design of the throttled channel allows the channel to be relatively long and to have a correspondingly large cross-section, so that clogging caused by impurities entrained by the damping medium is prevented.
  • the desired damping effect can be achieved in a simple manner by modifying, as needed, the length and the cross-section of the channel.
  • Such a relatively large cross-section of the channel has the advantage that impurities which might be entrained in the damping medium cannot deposit, but are instead removed from the throttled channel by the damping medium.
  • the throttled channel extends in the plane perpendicular to the axis of the piston along an angle or more than 360°. Due to the spiral design, it is thus easy to provide a throttled passage of great length at one front end of the piston. In order to achieve a predetermined flow resistance, the cross-section of said throttled channel can, therefore, be correspondingly large. For this reason, the pitch selected for the spiral is decisive for the length of the channel and can be readily adapted to the required damping effect.
  • At least one axial bore provided within the piston body terminates in the throttled channel in the region of its radially inner end, to make sure that damping fluid flows through the throttled channel over its entire length. It is of advantage to provide the axial bores with larger cross-sections than the throttled channel so that merely the throttled channel acts as a damping means and no special requirements of the axial bore itself must be fulfilled. Hence the axial bore need not be provided after the piston has been manufactured, but can be made at the same time as the piston is sintered, die-cast or injection-molded.
  • the making of the throttled channel as such is very simple because, according to a further feature of the present invention, this throttled channel extends at the front end of the piston body and is covered by a piston plate.
  • the piston body including the throttled channel thus is simple and inexpensive to manufacture.
  • the present die-casting, sintering, and injection-molding techniques allow for high precision manufacture of the groove-shaped channel within the piston body.
  • the throttled channel is preferably covered by a piston plate which can be a planar member made of plastic material or of a composite material. It is also possible to provide this throttled channel in a piston plate. In either case, the radially outer end of the throttled channel terminates in one of the working chambers.
  • FIG. 1 shows a longitudinal section of a gas spring
  • FIG. 2 is an end view of the piston body according to line V--V of FIG. 1;
  • FIG. 3 shows a spiral throttled channel extending in the piston plate
  • FIG. 4 is a top view of the piston unit on the line IV--IV of FIG. 3;
  • FIG. 5 shows a piston having spiral throttled channels extending in both front faces of the piston body.
  • the preferred embodiment of the present invention is a gas spring which presents a pneumatic installation, and which produces an outward force acting on the piston rod which corresponds to the product of the cross-sectional area of the piston rod and the pressure within the cylinder.
  • the invention can of course be used for any other pneumatic, hydraulic, or hydropneumatic installations in which a dampened movement of the piston rod is to be provided.
  • damping means are used to prevent rapid movement of the piston rod.
  • the gas spring shown in FIG. 1 has a cylinder 1 in which slides a piston 5 connected to a piston rod 4.
  • Guide means 2 for the piston rod 4 and the piston rod sealing means 3 are positioned at one end of the cylinder.
  • the piston 5 mounted on the extension 13 of the piston rod 4 separates the cavity of the cylinder 1 into a working chamber 14 above the piston and into a working chamber 15 below the piston. These working chambers 14 and 15 are filled with pressurized gas.
  • the piston 5 includes the piston body 6 disposed between the piston plate 9 and the piston disc 10.
  • An annular recess within the piston body 6, together with the piston disc 10, define an annular groove 11 in the piston which is larger than a piston ring 12 both in axial and in radial direction.
  • the piston body 6 further comprises an axial bore 7 connected to the throttled channel 8.
  • This axial bore 7 and the throttled channel 8 define the constantly open passage between the working chamber 14 and the working chamber 15.
  • FIG. 2 shows the throttled channel 8 positioned within the piston body 6, and it can be seen that the axial bore 7 ends in the channel 8 in the region of the radially inner end thereof and that this channel 8 extends spirally on the lower front side of the piston body 6.
  • the exit of the throttled channel 8 into the working chamber 15 extends approximately tangentially to the peripheral surface of the piston body 6.
  • FIG. 1 clearly shows that the throttled channel is defined by the piston body 6 and the piston plate 9. This arrangement of the throttled channel allows a very simple manufacture.
  • FIGS. 3 and 4 differs from that shown in FIGS. 1 and 2 principally in that a plurality of axial bores 7 are provided in the piston body 6 which terminate in an annular channel 16 extending in the piston body 6.
  • the piston 5 also includes the piston body 6 mounted on the extension 13 of the piston rod 4 between the piston disc 10 and the piston plate 9.
  • the spiral throttled channel 17 extends in the piston plate 9 and is covered by the piston body 6.
  • the annular channel 15 of the piston body 6 communicates with the throttled channel 17 in the region of the radially inner end of the throttled channel 17.
  • the piston body 6 is provided with spiral throttled channels on both sides thereof.
  • the throttled channel 20 covered by the piston disc 18 has an inlet slot 21 at its radially outer end, and terminates at its radially inner end in the axial bore 7.
  • This axial bore 7 connects the throttled channel 20 to the throttled channel 8, which is covered by the piston plate 9 and has an outlet slot at its radially outer end.
  • the throttled channels 8 and 20 are connected in series.
  • the piston disc 18 is provided with recesses 19.
  • the piston ring 12 engages the contact face defined by the piston disc 18 due to the friction caused on the inner peripheral face of the cylinder 1.
  • the recesses 19 and the annular groove 11 of the piston as well as the annular gap 26 defined between the piston body 6 and the cylinder 1 permit the unrestricted flow of the damping medium from the working chamber positioned below the piston into the working chamber positioned above the piston.
  • Such a design is suited in particular for use in installations in which a great damping effect is needed when the piston rod moves out of the cylinder or when throttled channels having a relatively large cross-section are desired.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Fluid-Damping Devices (AREA)
US06/306,383 1980-10-22 1981-09-28 Piston for a pneumatic, hydraulic, or hydropneumatic installation Expired - Fee Related US4438833A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19803039801 DE3039801A1 (de) 1980-10-22 1980-10-22 Kolben fuer ein pneumatisches, hydraulisches oder hydropneumatisches aggregat
DE3039801 1980-10-22

Publications (1)

Publication Number Publication Date
US4438833A true US4438833A (en) 1984-03-27

Family

ID=6114926

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/306,383 Expired - Fee Related US4438833A (en) 1980-10-22 1981-09-28 Piston for a pneumatic, hydraulic, or hydropneumatic installation

Country Status (6)

Country Link
US (1) US4438833A (xx)
JP (1) JPS57101143A (xx)
BR (1) BR8106541A (xx)
DE (1) DE3039801A1 (xx)
ES (1) ES269684Y (xx)
FR (1) FR2492491B1 (xx)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4881723A (en) * 1985-08-03 1989-11-21 Fritz Bauer + Sohne Ohg Double-damped gas spring with friction liner and sealing ring
US4989700A (en) * 1989-12-28 1991-02-05 Fichtel & Sachs Industries, Inc. Gas spring with an anti-rattle piston assembly
US5070972A (en) * 1990-06-18 1991-12-10 General Motors Corporation Vortex valving assembly for a hydraulic damper
US5460251A (en) * 1994-09-13 1995-10-24 Avm, Inc. Adjustable speed gas spring
US5579874A (en) * 1994-09-13 1996-12-03 Avm, Inc. Adjustable speed gas spring
WO1997033102A1 (en) * 1996-03-07 1997-09-12 Avm, Inc. Temperature compensated safety gas spring
US5775677A (en) * 1995-02-07 1998-07-07 Englund; Arlo C. Air or gas sprung and dampened shock absorber
US6533084B2 (en) * 2001-05-07 2003-03-18 Samhongsa Co., Ltd. Gas spring device
US20050040574A1 (en) * 2003-08-19 2005-02-24 Ivers Douglas E. Pneumatic surface effect damper
US20080006494A1 (en) * 2004-02-10 2008-01-10 Bart Vandewal Electronically controlled frequency dependent damping
CN100587291C (zh) * 2007-11-05 2010-02-03 迪斯油压工业(昆山)有限公司 油压缓冲器
WO2010124945A1 (de) 2009-04-28 2010-11-04 Druck- und Spritzgußwerk Hettich GmbH & Co. KG Dämpfer für möbel
CN102587776A (zh) * 2012-03-07 2012-07-18 卫德义 环沟槽式强阻尼微孔液压阻尼器
CN104044296A (zh) * 2013-03-14 2014-09-17 迪斯油压工业(昆山)有限公司 结构改进的缓冲器回油装置
US11268589B2 (en) 2017-11-24 2022-03-08 Martin Zimmer Cylinder-piston unit with load-dependent throttle

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3168515D1 (en) * 1980-10-14 1985-03-07 Nissan Motor Shock absorber with vortex flow guide
JPH0239066Y2 (xx) * 1984-09-26 1990-10-19
NL8500145A (nl) * 1985-01-21 1986-08-18 Koni Bv Hydraulische tweepijpsschokdemper.
JPS639532U (xx) * 1986-07-07 1988-01-22
DE3810841C2 (de) * 1987-04-08 1997-07-03 Juergen Voelckers Mit Gasfüllung oder Gaspolster arbeitender Teleskopdämpfer
DE3931448A1 (de) * 1989-09-21 1991-04-04 Stabilus Gmbh Stufenlos hoehenverstellbares, hydropneumatisches hubaggregat, mit ueberdrucksicherung
FR2666857B1 (fr) * 1990-09-17 1992-12-18 Ecia Equip Composants Ind Auto Amortisseur lineaire a gaz a simple effet.
JP4740045B2 (ja) * 2006-06-15 2011-08-03 株式会社ショーワ 油圧緩衝器の減衰バルブ
JP5933286B2 (ja) * 2012-02-22 2016-06-08 Ｋｙｂ株式会社 油圧ダンパ
DE102012103619A1 (de) * 2012-04-25 2013-10-31 Druck- und Spritzgußwerk Hettich GmbH & Co. KG Dämpfer

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB371764A (en) * 1930-11-20 1932-04-28 Paul Louis Lemoine Improvements in or relating to fluid actuated regulating valves
FR845638A (fr) * 1937-11-10 1939-08-29 Kronprinz Ag Fu R Metallindust Dispositif de suspension applicable par exemple aux trains d'atterrissage pour avions
GB728495A (en) * 1952-12-08 1955-04-20 British Thomson Houston Co Ltd Improvements in and relating to dash-pot type shock absorbers
US3323550A (en) * 1964-05-21 1967-06-06 Lee Co Fluid resistor
US3362508A (en) * 1966-06-06 1968-01-09 Bendix Corp Variable vortex piston device
GB1271268A (en) * 1968-06-06 1972-04-19 Robertshaw Controls Co Restricted bypass flow check valve
DE2057275A1 (de) * 1970-11-21 1972-05-31 Fichtel & Sachs Ag Progressivdaempfer,einstellbar ueber Veraenderung der Durchflusslaenge
US3672474A (en) * 1970-02-16 1972-06-27 Bendix Corp Fluid flow device for a shock absorber
GB1483474A (en) * 1973-12-03 1977-08-17 Sybron Corp Fluid resistors
DE7833144U1 (de) * 1978-11-08 1979-03-01 Stabilus Gmbh, 5400 Koblenz Druckgasgefüllte Gasfeder

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1068219A (fr) * 1952-12-08 1954-06-23 Alsthom Cgee Perfectionnement aux dash-pots et autres amortisseurs à liqunie
BE630954A (xx) * 1962-05-11
US3133615A (en) * 1962-07-02 1964-05-19 Bendix Corp Hydraulic shock absorber with improved piston valve means
FR1380784A (fr) * 1962-10-30 1964-12-04 R I V Anstalt Zur Verwaltung V Perfectionnements aux dispositifs amortisseurs
DE1899218U (de) * 1964-01-31 1964-08-20 Stabilus Ind Und Handelsgesell Teleskopische gasfeder.
DE1898692U (de) * 1964-01-31 1964-08-13 Stabilus Ind Und Handelsgesell Teleskopische gasfeder.
GB1190943A (en) * 1966-09-02 1970-05-06 Peddinghaus Carl Ullrich Dr Improvements relating to Hydraulic Shock Absorbers
FR1540380A (fr) * 1967-04-25 1968-09-27 Piston pour amortisseurs de chocs, et amortisseurs de chocs utilisant ce piston
DE2727407C2 (de) * 1977-06-18 1982-05-27 Boge Gmbh, 5208 Eitorf Ventileinrichtung, insbesondere für Teleskopschwingungsdämpfer von Kraftfahrzeugen
DE2905091C2 (de) * 1979-02-10 1981-10-01 Fa. Carl Freudenberg, 6940 Weinheim Gummilager mit hydraulischer Dämpfung
JPS55124645U (xx) * 1979-02-27 1980-09-04
DE2950888A1 (de) * 1979-12-18 1981-06-25 Stabilus Gmbh Daempfkolben fuer pneumatische, hydraulische und hydropneumatische aggregate

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB371764A (en) * 1930-11-20 1932-04-28 Paul Louis Lemoine Improvements in or relating to fluid actuated regulating valves
FR845638A (fr) * 1937-11-10 1939-08-29 Kronprinz Ag Fu R Metallindust Dispositif de suspension applicable par exemple aux trains d'atterrissage pour avions
GB728495A (en) * 1952-12-08 1955-04-20 British Thomson Houston Co Ltd Improvements in and relating to dash-pot type shock absorbers
US3323550A (en) * 1964-05-21 1967-06-06 Lee Co Fluid resistor
US3362508A (en) * 1966-06-06 1968-01-09 Bendix Corp Variable vortex piston device
GB1271268A (en) * 1968-06-06 1972-04-19 Robertshaw Controls Co Restricted bypass flow check valve
US3672474A (en) * 1970-02-16 1972-06-27 Bendix Corp Fluid flow device for a shock absorber
DE2057275A1 (de) * 1970-11-21 1972-05-31 Fichtel & Sachs Ag Progressivdaempfer,einstellbar ueber Veraenderung der Durchflusslaenge
GB1483474A (en) * 1973-12-03 1977-08-17 Sybron Corp Fluid resistors
DE7833144U1 (de) * 1978-11-08 1979-03-01 Stabilus Gmbh, 5400 Koblenz Druckgasgefüllte Gasfeder

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
"Technical Hydraulic Handbook", 5th Ed., The Lee Company, Westbrook, Connecticut, pp. 88-131, (1971).
Technical Hydraulic Handbook , 5th Ed., The Lee Company, Westbrook, Connecticut, pp. 88 131, (1971). *

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4881723A (en) * 1985-08-03 1989-11-21 Fritz Bauer + Sohne Ohg Double-damped gas spring with friction liner and sealing ring
US4989700A (en) * 1989-12-28 1991-02-05 Fichtel & Sachs Industries, Inc. Gas spring with an anti-rattle piston assembly
US5070972A (en) * 1990-06-18 1991-12-10 General Motors Corporation Vortex valving assembly for a hydraulic damper
US5460251A (en) * 1994-09-13 1995-10-24 Avm, Inc. Adjustable speed gas spring
US5579874A (en) * 1994-09-13 1996-12-03 Avm, Inc. Adjustable speed gas spring
US5775677A (en) * 1995-02-07 1998-07-07 Englund; Arlo C. Air or gas sprung and dampened shock absorber
WO1997033102A1 (en) * 1996-03-07 1997-09-12 Avm, Inc. Temperature compensated safety gas spring
US5722643A (en) * 1996-03-07 1998-03-03 Avm, Inc. Temperature compensated safety gas spring
US6533084B2 (en) * 2001-05-07 2003-03-18 Samhongsa Co., Ltd. Gas spring device
US20050040574A1 (en) * 2003-08-19 2005-02-24 Ivers Douglas E. Pneumatic surface effect damper
US20080006494A1 (en) * 2004-02-10 2008-01-10 Bart Vandewal Electronically controlled frequency dependent damping
US8210330B2 (en) * 2004-02-10 2012-07-03 Tenneco Automotive Operating Company Inc. Electronically controlled frequency dependent damping
CN100587291C (zh) * 2007-11-05 2010-02-03 迪斯油压工业(昆山)有限公司 油压缓冲器
WO2010124945A1 (de) 2009-04-28 2010-11-04 Druck- und Spritzgußwerk Hettich GmbH & Co. KG Dämpfer für möbel
CN102421978A (zh) * 2009-04-28 2012-04-18 压铸及注塑厂海蒂诗有限责任两合公司 用于家具的缓冲器
US8668062B2 (en) 2009-04-28 2014-03-11 Konrad Weber Damper for furniture
EP2730735A1 (de) 2009-04-28 2014-05-14 Druck- und Spritzgußwerk Hettich GmbH & Co. KG Dämpfer für Möbel
CN102421978B (zh) * 2009-04-28 2014-05-14 压铸及注塑厂海蒂诗有限责任两合公司 用于家具的缓冲器
CN102587776A (zh) * 2012-03-07 2012-07-18 卫德义 环沟槽式强阻尼微孔液压阻尼器
CN104044296A (zh) * 2013-03-14 2014-09-17 迪斯油压工业(昆山)有限公司 结构改进的缓冲器回油装置
US11268589B2 (en) 2017-11-24 2022-03-08 Martin Zimmer Cylinder-piston unit with load-dependent throttle

Also Published As

Publication number Publication date
FR2492491B1 (xx) 1984-12-28
ES269684Y (es) 1984-02-16
DE3039801A1 (de) 1982-05-27
JPS57101143A (en) 1982-06-23
FR2492491A1 (xx) 1982-04-23
DE3039801C2 (xx) 1989-07-20
BR8106541A (pt) 1982-06-29
JPH024808B2 (xx) 1990-01-30
ES269684U (es) 1983-08-01

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